3. Observations
The Frixion pens contain a mobile, liquid ink and write very
smoothly producing ink-lines visually similar to ordinary liquidink
rollerball pens. Microscopically, the ink-lines exhibit the
following characteristics:
(i) a slightly indented groove central to the coloured line.
(ii) an extra deposit of ink where the pen lifts from the paper.
(iii) a “powdery” appearance as if the dried ink was finely granular.